1. Field of the invention
The present invention relates generally to a so-called three position hydraulic cylinder that is capable of being set at three positions, both end positions and a center position. In particular, the present invention relates to a three position hydraulic cylinder that is able to be manufactured in small sizes and allows easy preadjustment of all three positions.
2. Description Of The Related Art
Hydraulic cylinders that are capable of three set positions are well known in the prior art. Applications for such a device include actuators of cargo moving mechanisms or power cylinders for lift mechanism sorters the like. The conventional hydraulic cylinder of this type is actually composed of two cylinders in combination provided separately with each other. Pressure is selectively applied to one of the right or left cylinders to cause a stroke in those respective directions. When pressures are applied to both cylinders the device is set in the middle position.
The above-mentioned combination of two cylinders occupies a large area and is high in cost. Such is disadvantageous.